Molecular Gels for Tissue Engineering - Soft Fibrillar Materials: Fabrication and Applications - page 137

(a) (b) (c) (d)

(e) (i) (f)

(g) (j) (h)

Figure 4.5 Generation of blood vessel on
rat cornea. Rat cornea was pictured 10 days
for blood vessel generation to assess the ef-
fect on angiogenesis by the combination of
different materials. (A) Heparin-nucleated
PA nanofiber with growth factors; (B) col-
lagen, heparin, and growth factors; (C) col-
lagen with growth factors; (D) heparin with
growth factors; (E) collagen with heparin;
(F) Heparin-nucleated PA with growth fac-
tors; (G) PA-heparin without growth fac-
tors; (H) growth factors alone. In sharp
contrast to the intensive blood vessel re-
generation induced by combinations in A,

the combinations in B and C caused some
vessel regeneration and the combinations of
D to H showed little sign of vessel regen-
eration. (I) Image under scanning electron
microscopy showing the fiber bundles of
heparin-nucleated PA nanostructures (scale
bar = 2 μ m). (J) Diagram shows the cylindri-
cal structure of heparin-nucleated PA. Posi-
tively charged PA molecules are able to bind
to negatively charged heparin molecules.
The aggregation of heparin-nucleated PA fi-
nally takes the cylindered structure. (Figure
adapted from Ref. [46] (Copyright 2006)
American Chemical Society.)

4.4.2
Saccharide-Based Molecular Gels

Saccharide-based molecular assemblies have become attractive in their potential
applications in tissue engineering owing to their intrinsic biocompatibility.
Saccharides and their glyco-conjugates are rich in ECM, and those on the
cell surface play essential roles in traducing signals in and out of a cell.